Large Scale Central

Machinists help

Tools and Tips
#1

I’ve been studying 1890s Locomotive Drivers and one Rule of engineering stressed having an Odd number of Spokes in cast drivers. The indexing plate on my Deluxe Unimat 1, 6 in 1 lathe/mill is 3 rows of even numbers of holes. 36, 40, 48. So 4 holes on the 36 row should give 9 spokes, said Pooh hopefully. Unfortunately 9 won’t be enough in a bigger wheel… The other rows don’t seem to be of any use, maybe there’s an over lapping one?

What are my alternative options? Dividers and hand feed?

Another source said the rule of thumb was max of 10 3/4" of inner rim between spoke (centers)

Thanks,

John

#2

PS; I think it’s interesting that the counter weights hang on the outside of the wheel …

#3

John Caughey said:

PS; I think it’s interesting that the counter weights hang on the outside of the wheel …

That’s where the rods are???

I’m sure Gary will be along before long and probably be of some help to you.

Rick

#4

Rick Marty said:

John Caughey said:

PS; I think it’s interesting that the counter weights hang on the outside of the wheel …

That’s where the rods are???

-snip-

The hub offset clears the weight, but not by much.

John

#5

was a silent Bump!

#6

John,

Sorry for being late to reply to your post, but…here goes.

This is a shot of the right side drivers on my 1-1/2" scale Gene Allen ten wheeler. All of the counterweights on this engine are the same size as cast. The ONLY difference is the thickness of each counterweight…how far they extend beyond the rim and spokes. I believe there are 14 spokes on each wheel.

This is the center driver and the main driver. The weight on this wheel is a little thicker to allow for the weight of the main rod pin and the side rods on the front and rear of this pin. The pin is actually longer than the others because of the added rods. The pin and joint behind the main pin allows the side rode to flex up and down with the spring set-up on the locomotive for uneven track.

This is a view of the drivers on the left side. Both rear drivers AND front drivers have thinner counterweights because the pin is shorter. It only has the side side rod weight to compensate for.

My Dad and his partner owned a forging die shop in El Monte, CA and we had a pattern shop associated with the business. One of my friends was building a 1.6" scale GS-4 Daylight northern. He needed the drivers for that model and we contracted the work by building the wood patterns and casting the drivers for that engine. Those drivers were boxpok drivers, no spokes. We used actual Lima Locomotive Co. prints to produce EXACT scale drivers as used on #4449. All of the counterweights on those drivers were a different size AND shape. The counterweight on the main driver was huge having to balance almost 5000 pounds per side for one side rod and the main rod and the roller bearings in the rods! Just for kicks, take a look at a close-up of the drivers, side rods and main rods on that particular engine. And this technology was circa 1941! 80 inch diameter drivers and a few tons of rods, moving at 90 to 100 mph! Southern Pacific took pride in setting a glass of wine in the diner and NEVER spilling a drop during the entire 420 mile to San Francisco-Los Angels runs and back again.

Hope this helps.

#7

Well Hello Gary,

I knew about the counter weights, my only learning there was from the pic I posted showing all the weight on the outside of the wheel.

That was an after thought to my first part looking for a system to layout and machine a wheel with an odd number of spokes. With the index I have I can do ‘evens’ any way I could imagine, but the hole patterns only allow 9 spokes on the 36 hole course. I was hoping for an easy way to go odd on a larger wheel… oh well

Thanks for the reply.

I took one of those trains back when I was knee high to a grass hopper. The only lasting impression was when the conductor left the roof vents open in a tunnel! Phewwwie!

John

#8

John Caughey said:

Well Hello Gary,

I knew about the counter weights, my only learning there was from the pic I posted showing all the weight on the outside of the wheel.

That was an after thought to my first part looking for a system to layout and machine a wheel with an odd number of spokes. With the index I have I can do ‘evens’ any way I could imagine, but the hole patterns only allow 9 spokes on the 36 hole course. I was hoping for an easy way to go odd on a larger wheel… oh well

Thanks for the reply.

I took one of those trains back when I was knee high to a grass hopper. The only lasting impression was when the conductor left the roof vents open in a tunnel! Phewwwie!

John

John,

If you are saying you need some help laying out the odd spokes, I can draw that for you using MasterCam. Really simple to let the software do the job. All I need from you is your wheel dimensions and an email address so I can attach the finished drawing. Be glad to do it for you.

#9

Hi Gary,

I have a Unimat 1, a 6 in 1 that can be a lathe and a mill. It’s an aluminum and plastic hobby lathe. Yet it is accurate enough for my needs, I geared it down so I can mill hard wax. Lost wax castings are coming …

My indexing plate only has 3 rows of 36, 40 and 48 holes. I can do every 4th hole on the 36 row and get 9 spokes, but unless there’s a higher number that works out with multiple rotations, I’m sol .

Delusional thinking mebbe, but a circle keeps rolling… I had researched 1890s Drivers and engineering. Odd spokes was a must for the ride and cooling after casting. Did you know many cast spokes were hollow? 9 spokes is too few for a larger wheel bearing in mind a second directive of the time that the inner rim should be 10 3/4" or less between spokes…

I’m not worried about a drawing, I’m wanting to mill it. Looking for milling tricks. I can free hand the wax removal, but milling keeps the industrial clean lines.

Don’t fret, this wheel I’m casting first in sterling silver and I’m going to inlay and wear on my hat band. Be good for show and tell… brass will follow. Why just walk the walk when I’ve got fancy steps? (http://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-wink.gif)

John

#10

Milling out the spokes as you describe or going through Kozo’s method of silver soldering them in place are worthy ventures indeed… However,

I wonder if it would be clever to test out some modern technology and have shape ways 3D print them in composite metal? Perhaps you could still make the tires and crank pins to ensure longer wear?

#11

John Caughey said:

Hi Gary,

I have a Unimat 1, a 6 in 1 that can be a lathe and a mill. It’s an aluminum and plastic hobby lathe. Yet it is accurate enough for my needs, I geared it down so I can mill hard wax. Lost wax castings are coming …

My indexing plate only has 3 rows of 36, 40 and 48 holes. I can do every 4th hole on the 36 row and get 9 spokes, but unless there’s a higher number that works out with multiple rotations, I’m sol .

Delusional thinking mebbe, but a circle keeps rolling… I had researched 1890s Drivers and engineering. Odd spokes was a must for the ride and cooling after casting. Did you know many cast spokes were hollow? 9 spokes is too few for a larger wheel bearing in mind a second directive of the time that the inner rim should be 10 3/4" or less between spokes…

I’m not worried about a drawing, I’m wanting to mill it. Looking for milling tricks. I can free hand the wax removal, but milling keeps the industrial clean lines.

Don’t fret, this wheel I’m casting first in sterling silver and I’m going to inlay and wear on my hat band. Be good for show and tell… brass will follow. Why just walk the walk when I’ve got fancy steps? (http://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-wink.gif)

John

OK John,

I finally understand what you are doing. Your indexing head doesn’t have the variety of holes to get your odd number of spokes. Try this article and make your own dividing head divisions and then jury-rig some kind of pointer to pick the holes. Probably more than accurate enough for what your doing.

http://home.kleppnett.no/thorhansen/m/EmcoUnimatDH.pdf

John,

I can make a drawing of the plate with the added “holes” and then do a full-size plot and literally send it to you in the mail! When I do a plot in MasterCam, it will be exact. You can literally check the dimensions with a mic or calipers. We used to do this when checking die layouts quickly especially when we had hole locations for knock-out pins in cavities and had to do a “quick and dirty” check on the run. Let me know.

#12

That works!

I’ll measure the original plate and send you the specs, there isn’t room to add a row. Already have a spring loaded pointer attachment for the original plate.

I’m busy this morning, but will send you the details later today.

Thanks buddy,

John

#13

John Caughey said:

That works!

I’ll measure the original plate and send you the specs, there isn’t room to add a row. Already have a spring loaded pointer attachment for the original plate.

I’m busy this morning, but will send you the details later today.

Thanks buddy,

John

Do you need my email address? Send me a PM and I will give you my email addie.